diff --git a/detection-rules/spam_emoji_cash_lures.yml b/detection-rules/spam_emoji_cash_lures.yml new file mode 100644 index 00000000000..3e310933ee7 --- /dev/null +++ b/detection-rules/spam_emoji_cash_lures.yml @@ -0,0 +1,31 @@ +name: "Display Name Emoji with Financial Symbols" +description: "Detects messages where the sender's display name contains emoji characters alongside financial symbols ($ £ € ¥ ₿) in the subject line. The sender's domain is not present in the Alexa top 1 million sites and has DMARC authentication issues." +type: "rule" +severity: "low" +source: | + // Hunt for emails with emoji in sender display name and financial symbols in subject + type.inbound + // Check for emoji in sender display name using Unicode ranges + and regex.contains(sender.display_name, + '[\x{1F600}-\x{1F64F}]|[\x{1F300}-\x{1F5FF}]|[\x{1F680}-\x{1F6FF}]|[\x{1F1E0}-\x{1F1FF}]|[\x{2600}-\x{26FF}]|[\x{2700}-\x{27BF}]' + ) + // Check for financial symbols in subject + and regex.contains(subject.subject, '[\$£€¥₿]') + + and ( + headers.auth_summary.dmarc.pass is null + or headers.auth_summary.dmarc.pass == false + ) + and sender.email.domain.root_domain not in $alexa_1m + +attack_types: + - "BEC/Fraud" + - "Callback Phishing" +tactics_and_techniques: + - "Social engineering" + - "Evasion" +detection_methods: + - "Content analysis" + - "Header analysis" + - "Sender analysis" +id: "f316f335-51ac-5ead-a059-53fdcb0cb50c"